An experiment was carried out to examine the effects of light quality on the growth and development of antirrhinum under three different temperatures 19 degrees C, 24 degrees C and 27 degrees C in glasshouses. Five different colour filters (i.e. 'Red absorbing', 'Blue absorbing', 'Blue and Red absorbing' and two 'partially Blue absorbing' materials) were tested, with one clear polythene as a control. Plant height, internode length and leaf area were significantly affected by the spectral filters as well as the temperature. Analysis of color filter's effect on presumed photoreceptors to exist indicated that antirrhinum plant height was regulated by the action of a blue acting photoreceptor (BAP) and not the phytochrome. There was no evidence for an effect of phytochrome or BAP on time to flowering, however, increasing temperature levels effectively decreased the time to flowering. To predict the effects of different spectral qualities and temperature, simple models were created from data on plant height, internode length and time to flowering. These models were then applied to simulate the potential benefits of spectral filters and temperature in manipulation of growth control and flowering in antirrhinum.
Antirrhinum ; growth & development ; radiation effects ; Dose-Response Relationship, Radiation ; Light ; Radiation Dosage ; Temperature

OBJECTIVETo investigate the injuries of intestinal mitochondria induced by different doses of whole-body radiation in Tibet minipigs.

METHODSEighteen Tibet minipigs were randomized into 5 radiation groups (n=3) and a control group (n=3). The minipigs in the radiation groups were subject to a total body X-ray radiation at 2, 5, 8, 11, or 14 Gy, and 72 h after the exposure, the mRNA expressions of the intestinal mitochondrial genes were examined using RT-PCR. The changes in the respiratory chain complexes I-IV and the respiratory functions of succinate and NADH were assayed, and the intestinal ultrastructures were observed using transmission electron microscopy (TEM) following the exposures.

RESULTSCompared with those in the control group, the expression levels of the related mitochondrial genes, the activities of the respiratory chain complexes and the function of the respiratory chain were significantly lowered in the radiation groups. At the doses below 8 Gy, the exposures caused significant reduction in the measurements as the radiation doses increased, but at higher doses, these measurements showed no further reductions. Ultrastructurally, exposures at 2 and 5 Gy caused mitochondrial expansion and mild reduction of the density, whereas radiation at 8 Gy or greater resulted in vacuolar changes and obvious expansion of the mitochondria with damages of the mitochondrial cristae and membranes.

CONCLUSIONBelow the doses of 8 Gy, intestinal mitochondrial damages in the minipigs increase with the radiation dose, but at higher doses, the damages do not further increase with the radiation dose.

Animals ; Dose-Response Relationship, Radiation ; Intestines ; cytology ; radiation effects ; Male ; Mitochondria ; radiation effects ; Radiation Dosage ; Swine ; Swine, Miniature

This study was purposed to investigate the mechanism of low dose radiation (LDR) by proteomic technology and to find the key proteins of the hormesis and adaptive response induced LDR, which provided the foundation of experimental and theoretical basis for the clinical application of LDR. Two-dimensional electrophoresis (2-DE) was used to screen protein patterns of normal serum and serum of mice exposed to LDR in different time for qualitative and quantitative differences in protein expression. And the differentially-expressed proteins between the two groups were identified by matrix assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS). The result showed that among the differentially-expressed proteins between the group exposed to LDR and the control group (shom-irradiated group), it was found that after LDR new 4 proteins appeared, 13 proteins were up-regulated, 6 proteins were down-regulated, 3 proteins disappeared in the group exposed to LDR. In different time the quantity of some proteins was different, the protein expression had some characteristics, the estrogen receptor 2 was down-regulated, the vitamin D-binding protein and apolipoprotien were up-regulated in the group exposed to LDR. It is concluded that LDR up-regulate or down-regulate some proteins, some proteins related with LDR were found. It may provide some new explanations for the effect mechanism of the LDR.
Animals ; Dose-Response Relationship, Radiation ; Estrogen Receptor beta ; blood ; radiation effects ; Male ; Mice ; Proteome ; radiation effects ; Radiation Dosage ; Serum ; radiation effects ; Vitamin D-Binding Protein ; blood ; radiation effects

This paper describes the development of TBI technique about fractionated TBI and the relationship between irradiation dose rate and complication; IMRT for TBI and lung compensation technique.
Dose-Response Relationship, Radiation ; Humans ; Radiation Dosage ; Whole-Body Irradiation ; methods

OBJECTIVETo investigate the ultrastructural variation of the facial nerve of rabbit with different dosage of (125)I seed brachytherapy.

METHODSFifty-four big ear rabbits were divided into 3 groups randomly and given 40 Gy, 80 Gy, 120 Gy respectively. Radioactive seeds were implanted in one side of parotid gland, the other side was implanted with vacant shell as a control group. The facial nerves were obtained 2, 4, 6 months respectively after operation and the histological ultrastructural changes observed by electromicroscope.

RESULTSIn the control group, epineurium was continuous, there was slight pitting edema under the epineurium, and axonal myelin was loose. In the test groups, there was slight pitting edema under the epineurium, and axonal myelin sheath was loose at 4th month. Macrophage and regenerated fibers were found in the 80 Gy group and myelin sheath lamellar separation, regeneration of nerve in the 120 Gy dosage. The myelin sheath lamellar was separated and axonal myelin loose in the test group at 6th month. Myelin sheath amellar separation and edema under the epineurium were found in the group of 80 Gy and 120 Gy.

CONCLUSIONSThe ultrastructure of the facial nerve is damaged by the dosage of 40 Gy, 80 Gy brachytherapy with (125)I seeds. The higher dosage the nerve receives, the more serious the damage will be. Both of the epineurium and axonal myelin sheath are integral and continuous 6 months after operation with dosage of 120 Gy.

Animals ; Brachytherapy ; Dose-Response Relationship, Radiation ; Facial Nerve ; radiation effects ; ultrastructure ; Female ; Iodine Radioisotopes ; administration & dosage ; radiation effects ; Male ; Rabbits ; Radiation Injuries, Experimental ; pathology ; Random Allocation

The purpose of this study is to investigate the mechanism of alternative responses to low dose irradiation for neuronal cell proliferation in the dentate gyrus of rats. To determine the effect of a single exposure to radiation, rats were irradiated with a single dose of 0.1, 1, 10 or 20 Gy. To determine the effect of the cumulative dose, the animals were irradiated daily with 0.01 Gy or 0.1 Gy from 1 to 4 days. The neuronal cell proliferation was evaluated using immunohistochemistry for 5-bromo-2'-deoxyuridine (BrdU), Ki-67 and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) staining. Four consecutive daily irradiations with a 0.01 Gy/fraction increased the number of BrdU-positive and Ki-67-positive cells in a dose dependent manner, but this did not affect the number of TUNEL-positive cells. However, there was not a dose dependent relationship for the 0.1 Gy/fraction irradiation with the number of BrdU, Ki-67 and TUNEL positive cells. Our data support the explanation that the adaptive response, induced by low-dose radiation, in the hippocampus of rats is more likely a reflection of the perturbations of cell cycle progression.
Rats, Sprague-Dawley ; Rats ; Radiation Dosage ; Neurons/*cytology/*radiation effects ; Neuronal Plasticity/*radiation effects ; Male ; Dose-Response Relationship, Radiation ; Dentate Gyrus/*cytology/*radiation effects ; Cell Survival/radiation effects ; Cell Proliferation/*drug effects ; Animals ; Adaptation, Physiological/radiation effects

OBJECTIVETo implement simultaneous integrated boost intensity-modulated radiotherapy(SIB-IMRT) plans for upper esophageal carcinoma and investigate the dose profiles of tumor and electively treated region and the dose to organs at risk (OARs).

METHODSSIB-IMRT plans were designed for two patients with upper esophageal carcinoma. Two target volumes were predefined: PTV1, the target volume of the primary lesion, which was given to 67.2 Gy, and PTV2, the target volume of electively treated region, which was given to 50.4 Gy. With the same dose-volume constraints, but different beams arrangements (3, 5, 7, or 9 equispaced coplanar beams), four plans were generated. Indices, including dose distribution, dose volume histogram (DVH) and conformity index, were used for comparison of these plans.

RESULTSThe plan with three intensity-modulated beams could produce good dose distribution for the two target volumes. The dose conformity to targets and the dose to OARs were improved as the beam number increased. The dose distributions in targets changed little when the beam number increased from 7 to 9.

CONCLUSIONSFive to seven intensity-modulated beams can produce desirable dose distributions for simultaneous integrated boost (SIB) treatment for upper esophageal carcinoma. The primary tumor can get higher equivalent dose by SIB treatments. It is easier and more efficient to design plans with equispaced coplanar beams. The efficacy of SIB-IMRT remains to be determined by the clinical outcome.

Aged ; Dose-Response Relationship, Radiation ; Esophageal Neoplasms ; radiotherapy ; Female ; Humans ; Male ; Radiation Dosage ; Radiotherapy Planning, Computer-Assisted ; methods

BACKGROUND/AIMS: Recently, several studies have revealed that diagnostic imaging can result in exposure to harmful levels of ionizing radiation in inflammatory bowel disease patients. However, the extent of radiation exposure in intestinal Behcet disease (BD) patients has not been documented. The aim of this study was to estimate the radiation exposure from abdominal imaging studies in intestinal BD patients. METHODS: Patients with a diagnosis of intestinal BD established between January 1990 and March 2012 were investigated at a single tertiary academic medical center. The cumulative effective dose (CED) was calculated retrospectively from standard tables and by counting the number of abdominal imaging studies performed. High exposure was defined as CED >50 mSv. RESULTS: In total, 270 patients were included in the study. The mean CED was 41.3 mSv, and 28.1% of patients were exposed to high levels of radiation. Computed tomography (CT) accounted for 81.7% of the total effective dose. In multivariate analyses, predictors of high radiation exposure were azathioprine/6-mercaptopurine use, surgery, and hospitalization. CONCLUSIONS: Approximately a quarter of intestinal BD patients were exposed to harmful levels of diagnostic radiation, mainly from CT examination. Clinicians should reduce the number of unnecessary CT examinations and consider low-dose CT profiles or alternative modalities such as magnetic resonance enterography.
Abdomen/radiation effects ; Adult ; Behcet Syndrome/*radiography ; Dose-Response Relationship, Radiation ; Female ; Humans ; Intestinal Diseases/*radiography ; Male ; Radiation Dosage ; Retrospective Studies ; Risk Factors

OBJECTIVETo evaluate the effect of Long-term exposure to low intensity microwave radiation on male reproductivity.

METHODSA total of 289 married male radar operators were included in the radar group and 148 married men unexposed to microwave radiation were enrolled as controls. Questionnaires were used and the intensity of microwave radiation in different working areas was detected.

RESULTSThe rate of sexual dysfunction was 43.6% in the radar group and 24.4% in the control group (P < 0.01). The natural pregnancy rate was 53.6% within 1 year of marriage and 46.4% after 1 year of marriage in the radar group, as compared with 81.1% and 18.9% in the control group (P < 0.01).

CONCLUSIONLong-term exposure to low intensity microwave radiation evidently increased the sexual dysfunction rate and decreased natural pregnancy rate in men.

Dose-Response Relationship, Radiation ; Erectile Dysfunction ; epidemiology ; Female ; Fertility ; radiation effects ; Humans ; Male ; Microwaves ; adverse effects ; Military Personnel ; Occupational Exposure ; Pregnancy ; Pregnancy Outcome ; Radar ; Radiation Dosage ; Surveys and Questionnaires

OBJECTIVE: To observe the influence of the single different radiation dose and time on the microscopic structure and ultrastructure of Balb/c Mice. METHOD: Sixteen four-week-old mice were randomly divided into four groups, control group and three experimental groups, then every experimental group was randomly divided into two groups which were respectively sacrificed on the third and seventh day after exposure to different doses of 8, 12, 16 Gy radiation, then paraffin embedding, tissue section, HE staining and scanning electron microscope, observation were performed after a cochlear specimen collected. RESULT: Inner hair cells and outer hair cells arranged in order, no lodging, disorder or missing in control group under scanning electron microscope. Slight lodgy or disorder occured in inner cells and outer hair cells were missing sometimes in exposed animals,which meat irrespective of irradiation dose. CONCLUSION Slight changes of ultrastructure of Balb/c Mice occured in the early period when given eaqual to or less than 16 Gy radiation.
Animals ; Cochlea ; radiation effects ; ultrastructure ; Dose-Response Relationship, Radiation ; Male ; Mice ; Mice, Inbred BALB C ; Microscopy, Electron, Scanning ; Radiation Dosage ; Time Factors